Losing connection to Interbase database server ?

Has anybody experienced similar problems/errors to this :-

Error reading cmbOfficerInitials.active  General SQL error - unable to
complete network request to host rd_nov_010.  Error writing data to
connection.

The cmbOfficerInitials is a combobox and is trying to refresh the SQL
picklist.  The Novell/Interbase server is rd_nov_010.  The sequence of
events to sometimes cause this problem are :-

(a)  The selects 'new application'.  Several DataSets are set to an INSERT
status.
(b)  The user enters the require fields for a new record.
(c)  The user then tries to post the new record and sometimes the General
SQL error occurs ?

To me it seems like the application is somehow losing its connection to the
server ?  The user with this problem is running from a WAN (384k) type
connection.

Any help on this problem would be greatly received.

Thanks very much

Stef Fiorentini